<?php

defined('_JEXEC') or die('Restricted access');
/**
 * PHP Hooks Class
 *
 * The PHP Hooks Class is a fork of the WordPress filters hook system rolled in to a class to be ported 
 * into any php based system
 *
 * This class is heavily based on the WordPress plugin API and most (if not all) of the code comes from there.
 * 
 * 
 * @version 0.1.1
 * @copyright 2011 - 2012
 * @author Ohad Raz (email: admin@bainternet.info)
 * @link http://en.bainternet.info
 * 
 * @license GNU General Public LIcense v3.0 - license.txt
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package PHP Hooks
 */
if (!class_exists('Hooks')) {

    /**
     * Hooks
     */
    class Hooks {

        /**
         * $filters holds list of hooks
         * @access public
         * @since 0.1
         * @var array
         */
        var $filters = array();

        /**
         * $merged_filters
         * @var array
         */
        var $merged_filters = array();

        /**
         * $actions 
         * @var array
         */
        var $actions = array();

        /**
         * $current_filter  holds the name of the current filter
         * @access public
         * @since 0.1
         * @var array
         */
        var $current_filter = array();

        /**
         * __construct class constructor
         * @access public
         * @since 0.1
         */
        public function __construct($args = null) {
            $this->filters = array();
            $this->merged_filters = array();
            $this->actions = array();
            $this->current_filter = array();
        }

        /**
         * FILTERS
         */

        /**
         * add_filter Hooks a function or method to a specific filter action.
         * @access public
         * @since 0.1
         * @param string $tag The name of the filter to hook the $function_to_add to.
         * @param callback $function_to_add The name of the function to be called when the filter is applied.
         * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action.
         * @param int $accepted_args optional. The number of arguments the function accept (default 1).
         * @return boolean true
         */
        public function add_filter($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
            $idx = $this->_filter_build_unique_id($tag, $function_to_add, $priority);
            $this->filters[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args);
            unset($this->merged_filters[$tag]);
            return true;
        }

        /**
         * remove_filter Removes a function from a specified filter hook.
         * @access public
         * @since 0.1
         * @param string $tag The filter hook to which the function to be removed is hooked.
         * @param callback $function_to_remove The name of the function which should be removed.
         * @param int $priority optional. The priority of the function (default: 10).
         * @param int $accepted_args optional. The number of arguments the function accepts (default: 1).
         * @return boolean Whether the function existed before it was removed.
         */
        public function remove_filter($tag, $function_to_remove, $priority = 10) {
            $function_to_remove = $this->_filter_build_unique_id($tag, $function_to_remove, $priority);

            $r = isset($this->filters[$tag][$priority][$function_to_remove]);

            if (true === $r) {
                unset($this->filters[$tag][$priority][$function_to_remove]);
                if (empty($this->filters[$tag][$priority]))
                    unset($this->filters[$tag][$priority]);
                unset($this->merged_filters[$tag]);
            }
            return $r;
        }

        /**
         * remove_all_filters Remove all of the hooks from a filter.
         * @access public
         * @since 0.1
         * @param string $tag The filter to remove hooks from.
         * @param int $priority The priority number to remove.
         * @return bool True when finished.
         */
        public function remove_all_filters($tag, $priority = false) {
            if (isset($this->filters[$tag])) {
                if (false !== $priority && isset($this->filters[$tag][$priority]))
                    unset($this->filters[$tag][$priority]);
                else
                    unset($this->filters[$tag]);
            }

            if (isset($this->merged_filters[$tag]))
                unset($this->merged_filters[$tag]);

            return true;
        }

        /**
         * has_filter  Check if any filter has been registered for a hook.
         * @access public
         * @since 0.1
         * @param string $tag The name of the filter hook.
         * @param callback $function_to_check optional.
         * @return mixed If $function_to_check is omitted, returns boolean for whether the hook has anything registered.
         *   When checking a specific function, the priority of that hook is returned, or false if the function is not attached.
         *   When using the $function_to_check argument, this function may return a non-boolean value that evaluates to false
         *   (e.g.) 0, so use the === operator for testing the return value.
         */
        public function has_filter($tag, $function_to_check = false) {
            $has = !empty($this->filters[$tag]);
            if (false === $function_to_check || false == $has)
                return $has;

            if (!$idx = $this->_filter_build_unique_id($tag, $function_to_check, false))
                return false;

            foreach ((array) array_keys($this->filters[$tag]) as $priority) {
                if (isset($this->filters[$tag][$priority][$idx]))
                    return $priority;
            }
            return false;
        }

        /**
         * apply_filters Call the functions added to a filter hook.
         * @access public
         * @since 0.1
         * @param string $tag The name of the filter hook.
         * @param mixed $value The value on which the filters hooked to <tt>$tag</tt> are applied on.
         * @param mixed $var,... Additional variables passed to the functions hooked to <tt>$tag</tt>.
         * @return mixed The filtered value after all hooked functions are applied to it.
         */
        public function apply_filters($tag, $value) {
            $args = array();
            // Do 'all' actions first
            if (isset($this->filters['all'])) {
                $this->current_filter[] = $tag;
                $args = func_get_args();
                $this->_call_all_hook($args);
            }

            if (!isset($this->filters[$tag])) {
                if (isset($this->filters['all']))
                    array_pop($this->current_filter);
                return $value;
            }

            if (!isset($this->filters['all']))
                $this->current_filter[] = $tag;

            // Sort
            if (!isset($this->merged_filters[$tag])) {
                ksort($this->filters[$tag]);
                $this->merged_filters[$tag] = true;
            }

            reset($this->filters[$tag]);

            if (empty($args))
                $args = func_get_args();

            do {
                foreach ((array) current($this->filters[$tag]) as $the_)
                    if (!is_null($the_['function'])) {
                        $args[1] = $value;
                        $value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args']));
                    }
            } while (next($this->filters[$tag]) !== false);

            array_pop($this->current_filter);

            return $value;
        }

        /**
         * apply_filters_ref_array Execute functions hooked on a specific filter hook, specifying arguments in an array.
         * @access public
         * @since 0.1
         * @param string $tag The name of the filter hook.
         * @param array $args The arguments supplied to the functions hooked to <tt>$tag</tt>
         * @return mixed The filtered value after all hooked functions are applied to it.
         */
        public function apply_filters_ref_array($tag, $args) {
            // Do 'all' actions first
            if (isset($this->filters['all'])) {
                $this->current_filter[] = $tag;
                $all_args = func_get_args();
                $this->_call_all_hook($all_args);
            }

            if (!isset($this->filters[$tag])) {
                if (isset($this->filters['all']))
                    array_pop($this->current_filter);
                return $args[0];
            }

            if (!isset($this->filters['all']))
                $this->current_filter[] = $tag;

            // Sort
            if (!isset($this->merged_filters[$tag])) {
                ksort($this->filters[$tag]);
                $this->merged_filters[$tag] = true;
            }

            reset($this->filters[$tag]);

            do {
                foreach ((array) current($this->filters[$tag]) as $the_)
                    if (!is_null($the_['function']))
                        $args[0] = call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
            } while (next($this->filters[$tag]) !== false);

            array_pop($this->current_filter);

            return $args[0];
        }

        /**
         * ACTIONS
         */

        /**
         * add_action Hooks a function on to a specific action.
         * @access public
         * @since 0.1
         * @param string $tag The name of the action to which the $function_to_add is hooked.
         * @param callback $function_to_add The name of the function you wish to be called.
         * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action.
         * @param int $accepted_args optional. The number of arguments the function accept (default 1).
         */
        public function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
            return $this->add_filter($tag, $function_to_add, $priority, $accepted_args);
        }

        /**
         * has_action Check if any action has been registered for a hook.
         * @access public
         * @since 0.1
         * @param string $tag The name of the action hook.
         * @param callback $function_to_check optional.
         * @return mixed If $function_to_check is omitted, returns boolean for whether the hook has anything registered.
         *   When checking a specific function, the priority of that hook is returned, or false if the function is not attached.
         *   When using the $function_to_check argument, this function may return a non-boolean value that evaluates to false
         *   (e.g.) 0, so use the === operator for testing the return value.
         */
        public function has_action($tag, $function_to_check = false) {
            return $this->has_filter($tag, $function_to_check);
        }

        /**
         * remove_action Removes a function from a specified action hook.
         * @access public
         * @since 0.1
         * @param string $tag The action hook to which the function to be removed is hooked.
         * @param callback $function_to_remove The name of the function which should be removed.
         * @param int $priority optional The priority of the function (default: 10).
         * @return boolean Whether the function is removed.
         */
        public function remove_action($tag, $function_to_remove, $priority = 10) {
            return $this->remove_filter($tag, $function_to_remove, $priority);
        }

        /**
         * remove_all_actions Remove all of the hooks from an action.
         * @access public
         * @since 0.1
         * @param string $tag The action to remove hooks from.
         * @param int $priority The priority number to remove them from.
         * @return bool True when finished.
         */
        public function remove_all_actions($tag, $priority = false) {
            return $this->remove_all_filters($tag, $priority);
        }

        /**
         * do_action Execute functions hooked on a specific action hook.
         * @access public
         * @since 0.1
         * @param string $tag The name of the action to be executed.
         * @param mixed $arg,... Optional additional arguments which are passed on to the functions hooked to the action.
         * @return null Will return null if $tag does not exist in $filter array
         */
        public function do_action($tag, $arg = '') {

            if (!isset($this->actions))
                $this->actions = array();

            if (!isset($this->actions[$tag]))
                $this->actions[$tag] = 1;
            else
                ++$this->actions[$tag];

            // Do 'all' actions first
            if (isset($this->filters['all'])) {
                $this->current_filter[] = $tag;
                $all_args = func_get_args();
                $this->_call_all_hook($all_args);
            }

            if (!isset($this->filters[$tag])) {
                if (isset($this->filters['all']))
                    array_pop($this->current_filter);
                return;
            }

            if (!isset($this->filters['all']))
                $this->current_filter[] = $tag;

            $args = array();
            if (is_array($arg) && 1 == count($arg) && isset($arg[0]) && is_object($arg[0])) // array(&$this)
                $args[] = & $arg[0];
            else
                $args[] = $arg;
            for ($a = 2; $a < func_num_args(); $a++)
                $args[] = func_get_arg($a);

            // Sort
            if (!isset($this->merged_filters[$tag])) {
                ksort($this->filters[$tag]);
                $this->merged_filters[$tag] = true;
            }

            reset($this->filters[$tag]);

            do {
                foreach ((array) current($this->filters[$tag]) as $the_)
                    if (!is_null($the_['function']))
                        call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
            } while (next($this->filters[$tag]) !== false);

            array_pop($this->current_filter);
        }

        /**
         * do_action_ref_array Execute functions hooked on a specific action hook, specifying arguments in an array.
         * @access public
         * @since 0.1
         * @param string $tag The name of the action to be executed.
         * @param array $args The arguments supplied to the functions hooked to <tt>$tag</tt>
         * @return null Will return null if $tag does not exist in $filter array
         */
        public function do_action_ref_array($tag, $args) {

            if (!isset($this->actions))
                $this->actions = array();

            if (!isset($this->actions[$tag]))
                $this->actions[$tag] = 1;
            else
                ++$this->actions[$tag];

            // Do 'all' actions first
            if (isset($this->filters['all'])) {
                $this->current_filter[] = $tag;
                $all_args = func_get_args();
                $this->_call_all_hook($all_args);
            }

            if (!isset($this->filters[$tag])) {
                if (isset($this->filters['all']))
                    array_pop($this->current_filter);
                return;
            }

            if (!isset($this->filters['all']))
                $this->current_filter[] = $tag;

            // Sort
            if (!isset($merged_filters[$tag])) {
                ksort($this->filters[$tag]);
                $merged_filters[$tag] = true;
            }

            reset($this->filters[$tag]);

            do {
                foreach ((array) current($this->filters[$tag]) as $the_)
                    if (!is_null($the_['function']))
                        call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
            } while (next($this->filters[$tag]) !== false);

            array_pop($this->current_filter);
        }

        /**
         * did_action Retrieve the number of times an action is fired.
         * @access public
         * @since 0.1
         * @param string $tag The name of the action hook.
         * @return int The number of times action hook <tt>$tag</tt> is fired
         */
        public function did_action($tag) {

            if (!isset($this->actions) || !isset($this->actions[$tag]))
                return 0;

            return $this->actions[$tag];
        }

        /**
         * HELPERS
         */

        /**
         * current_filter Retrieve the name of the current filter or action.
         * @access public
         * @since 0.1
         * @return string Hook name of the current filter or action.
         */
        public function current_filter() {
            return end($this->current_filter);
        }

        /**
         * _filter_build_unique_id Build Unique ID for storage and retrieval.
         * @param string $tag Used in counting how many hooks were applied
         * @param callback $function Used for creating unique id
         * @param int|bool $priority Used in counting how many hooks were applied. If === false and $function is an object reference, we return the unique id only if it already has one, false otherwise.
         * @return string|bool Unique ID for usage as array key or false if $priority === false and $function is an object reference, and it does not already have a unique id.
         */
        private function _filter_build_unique_id($tag, $function, $priority) {
            static $filter_id_count = 0;

            if (is_string($function))
                return $function;

            if (is_object($function)) {
                // Closures are currently implemented as objects
                $function = array($function, '');
            } else {
                $function = (array) $function;
            }

            if (is_object($function[0])) {
                // Object Class Calling
                if (function_exists('spl_object_hash')) {
                    return spl_object_hash($function[0]) . $function[1];
                } else {
                    $obj_idx = get_class($function[0]) . $function[1];
                    if (!isset($function[0]->filter_id)) {
                        if (false === $priority)
                            return false;
                        $obj_idx .= isset($this->filters[$tag][$priority]) ? count((array) $$this->filters[$tag][$priority]) : $filter_id_count;
                        $function[0]->filter_id = $filter_id_count;
                        ++$filter_id_count;
                    } else {
                        $obj_idx .= $function[0]->filter_id;
                    }

                    return $obj_idx;
                }
            } else if (is_string($function[0])) {
                // Static Calling
                return $function[0] . $function[1];
            }
        }

        /**
         * __call_all_hook
         * @access public
         * @since 0.1
         * @param  (array) $args [description]
         */
        public function __call_all_hook($args) {
            reset($this->filters['all']);
            do {
                foreach ((array) current($this->filters['all']) as $the_)
                    if (!is_null($the_['function']))
                        call_user_func_array($the_['function'], $args);
            } while (next($this->filters['all']) !== false);
        }

    }

    //end class
}//end if
global $hooks;
$hooks = new Hooks();
$hooks->do_action('After_Hooks_Setup', $hooks);